{(-1,7),(1,-9),(4,-9),(7,-5),(10,-3)}

Question

decide whether th relation is a function

Answer 1

Yes, it is a function because each unique value of x maps to one and only one value of y. All the values of x are different. The only repeated value is -9 which is a y value. (There is no inverse function, because -9 maps to two different values of x.)